1,3-dioxan-5-ylalkyltriazoles, their use for regulating plant growth, and agents for this purpose

ABSTRACT

Compounds of the formula I ##STR1## where R 1  and R 2  are identical or different and are each hyrogen or alkyl of 1 to 5 carbon atoms, the radicals X are identical or different substituents selected from the group consisting of halogen, cyano, trifluoromethyl, nitro, C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, unsubstituted or substituted phenyl or hydrogen, m is from zero to 5, n is an integer from 2 to 6 and Y is --CO-- or --CH(OH)--, their intermediates of the formula (II) ##STR2## and the use of the compounds (I) as plant growth regulators.

The present invention relates to novel 1,3-dioxan-5-ylalkyltriazoles,processes for their preparation and plant growth regulators containingthese compounds.

It is known that certain 2-haloethyl-trialkylammonium halides possessplant growth-regulating properties (cf. U.S. Pat. No. 3,156,554). Thus,plant growth can be influenced using (2-chloroethyl)-trimethylammoniumchloride. However, the effectiveness of this substance is not alwayssatisfactory, especially at low application rates.

It is also known that3,3-dimethyl-2-(1,2,4-triazol-1-1-yl)-1-(4-chlorobenzoyl)-butane can beused for regulating plant growth (German Laid-Open Application DOS No.2,739,352).

Furthermore, the plant growth-regulating action of3,3-dimethyl-2-(1,2,4-triazol-1-(4-chlorobenzoyl)-butane (GermanLaid-Open Application DOS No. 2,921,168) and of1-(5-methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-3-(4-trifuoromethylphenyl-propen-1-ol(German Laid-Open Application DOS No. 3,026,140) is known.

At least in the case of specific target orgnanisms, the action of thecompounds which are known growth regulators is unsatisfactory in respectof application rate, lack of side effects and morphospecific effect.

We have found that compounds of the formula I ##STR3## where R¹ and R²are identical or different and are each hydrogen or alkyl of 1 to 5carbon atoms, the radicals X are identical or different substituentsselected from the group consisting of halogen, cyano, trifluoromethyl,nitro, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, unsubstituted or substitutedphenyl and hydrogen, m is from zero to 5, n is an integer from 2 to 6and Y is --CO-- or --CH(OH)--, are very useful for influencing plantgrowth and are very well tolerated by plants; in the latter case thecompounds are diastereomers comprising in each case two pairs ofantipodes (enantiomers), which can have the configuration R*, S* orR*,R* at the two centers of chirality (cf. D. Seebach and V. Prelog,Angew. Chem. 94 (1982), 696 and the literature stated therein.

The present invention relates to both the diastereomers or diasteromericmixtures and to the pure enantiomers obtainable in a conventionalmanner.

R¹ and R² are each preferably hydrogen, methyl, ethyl, n-propyl,isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl orneopentyl.

X_(m) is preferably hydrogen, 2-fluoro-, 4-fluoro-, 2-chloro-,3-chloro-, 4-chloro-, 4-bromo-, 2,4-dichloro-, 2,6-dichloro-,3,4-dichloro, 2,4,6-trichloro-, 2-chloro-4-methyl, 2-methyl-4-chloro-,2-methyl-, 3-methyl-, 4-methyl-, 4-ethyl-, 4-isopropyl-, 4-tert-butyl-,2,4-dimethyl-, 2,4,6-trimethyl-, 2-methoxy-4-methyl-, 2-methoxy-,4-methoxy-, 4-ethoxy-, 2-trifluoromethyl-, 4-trifluoromethyl-, 4-cyano-,4-nitro- or 4-phenyl-.

The novel compounds can be prepared by a process in which

(a) 1,2,4-triazole is reacted with an appropriate α-bromoketone of theformula II ##STR4## or

(b) an appropreated aryloxyalkyl halide of the formula III ##STR5##where Z is halogen (chlorine or bromine), is reacted with an appropriate1-(1,3-dioxan-5-yl)-2-(1,2,4-triazolyl)ethan-1-one of the formula IVand, if required, the resulting compound is then reduced from the ketoneto the secondary alcohol.

Reactions (a) and (b) can be carried out similarly in a conventionalmanner, as can the reduction of ketone to the alcohol. Some of thereactants in these reactions are known (cf. European Pat. No. 69,290 andGerman Laid-Open Application DOS No. 3,025,879).

The bromoketones of the formula II arenovel compounds and can beobtained, for example, by bromination of appropriate compounds of theformula V ##STR6## with bromine in formamide (H. Bredereck et al., Chem.Ber. 93 (1960), 2083) or with dioxane dibromide (S. J. Pasariber and L.R. Williams, Aust. J. Chem. 26 (1973), 1327) or with the COmplex(pyrrolidone)₃.HBr.Br₂ (D. C. Awang et al., Can. J. Chem. 47 (1969)706).

The 1-(1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-ethan-1-ones of theformula IV can be obtained, for example, by reacting an appropriate2-holo-1-(2,5-dialkyl-1,3-dioxan-5-yl)-ethan-1-one of the formula VI##STR7## with 1,2,4-triazole or its alkali metal salt in a suitablesolvent.

The haloketones of the formula VI are obtained, for example, bybrominating a known 1,3-dioxan-5-ylethan-1-one of the formula VII##STR8## where R¹ and R² have the above meanings, for example with apyrrolidone-bromine complex, according to D. P. Wyman and P. R.Kaufmann, J. Org. Chem. 29 (1964), 1956.

The ketones obtained as described in (a) or (b) can, if desired, bereduced stereoselectively, this being done in a conventinal manner

(a) with a secondary alcoholate (EP-A-11 191),

(b) with an alkylmagnesium halide which contains an alkyl radical of 2to 6 carbon atoms and a beta hydrogen atom in the alkyl radical (cf.O.Z. 0050/36557) or

(c) with hydrogen in the presence of ruthenium or a rutheniumderivative, in particular ruthenium oxide hydroxide (cf. O.Z.0050/36557).

The resulting alcohols of te formula I have a substantially highercontent of the diastereomers with the R*,S* configuration than thosewith the R*,R* configuration. The content of the R*,R* diastereomers inthe mixture is as a rule well below 30%. Pure R*,S* diastereomers can beobtained from this mixture simply by washing the crude products withsuitable solvents, eg. diisopropyl ether, or by recrystallization oranother, conventional purification step, eg. chromatography.

In the diastereoselective reduction of the ketones with a complexhydride, preferably sodium borohydride, a metod which is likewise knownper se, the resulting alcohols have a substantially higher content ofthe diastereomers with the R*,R* configuration.

EXAMPLE 1

(a) Preparation of an intermediate

(aa) A solution of 498 g (1 mole) of pyrrolidone-bromine complex in 1 lof tetrahydrofuran is added dropwise to a solution of 144 g (1 mole) of5-acetyl-5-methyl-1,3-dioxene and 85.5 g (1 mole) of pyrrolidone in 500ml of tetrahydrofuran in the course of 2 hours at 50° C. Stirring iscontinued for 8 hours at 50° C., after which the white precipitate ofpyrrolidone hydrobromide is filtered off under suction and washed with50 ml of tetrahydrofuran, and the filtrate is evaporated down underreduced pressure. 220 g (99%) of crude, oily1-(5-methyl-1,3-dioxan-5-yl)-2-brommoethan-1-one are obtained.

(ab) A solution of 223 g (1 mole) of1-(5-methyl-1,3-dioxan-5-yl)-2-bromoethan-1-one in 200 ml oftetrahydrofuran is added dropwise, at 25° C. in the course of 2 hours,to a stirred suspension of 110.1 g (1.1 moles) of sodium1,2,4-triazolide in 300 ml of dry tetrahydrofuran, the suspension beingkept under nitrogen. The mixture is refluxed for 8 hours, after whichthe inorganic precipitate is filtered off and the filtrate is evaporateddown to half its volume.

The mixture is seeded and left to stand overnight at +3° C. Theprecipitate is filtered off under suction, washed with 30 ml of cold(+5° C.) tetrahydrofuan, then with 80 ml of ether and then with 100 mlof n-pentane, and dried. 184 g (87.2%) of 1-(5-methyl-1,3-dioxan-;b5-yl)-2-(1,2,4-triazol-1-yl)-ethan-1-one are obtained as white crystalsof melting point 95°-97° C.

(b) Preparation of an end product (compound no. 1 in the Table)

A solution of 42.2 g (0.2 mole) of1-(5-methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-ethan-1-one in 150ml of absolute dimethylformamide is added dropwise, at from 20° to 25°C., to a stirred suspension of 5.3 g (0.22 mole) of sodium hydride in 50ml of absolute dimethylformamide, the suspension being kept undernitrogen. Stirring is continued for 3 hours, after which a solution of49.4 g (0.2 mole) of 1-bromo-4-(2-fluorophenoxy)-butane in 50 ml ofabsolute dimethylformamide is added dropwise at 60° C. and the reactionmixture is then refluxed for a further 5 hours. About 100 ml of icewater are then carefully added dropwise at room temperature, and themixture is extracted with three times 300 ml of methylene chloride. Theorganic phase is then washed several times with water, dried over Na₂SO₄ and evaporated down. Distillation (bp.=248° C./0.005) gives 56 g(74%) of1-(5-methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-6(2-fluorophenoxy)-hexan-1-oneas a yellowish resin.

EXAMPLE 2

(1-R*,2-R*)-1-(5-Methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-6-(2-fluorophenoxy)-hexan-1-ol(compound no. 2 in the Table)

3.0 g (0.078 mole) of sodium borohydride are added a little at a time toa solution of 24.5 g (0.065 mole) of1-(5-methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-6-(2-fluorophenoxy)-hexan-1-onein 300 ml of methanol at from 0° to +5° C. The stirred mixture isrefluxed for 5 hours and then evaporated down, the residue ispartitioned between 400 ml of ether and 200 ml of water, and the ethersolution is washed three times with 200 ml of water, dried over sodiumsulfate and again evaporated down. The residue is chromatographed over asilica gel column using a 9:1 methylene chloride/acetone mixture, andthe solvent is removed. 13.2 g (54%) of the pure diastereomeric productare obtained in the form of white crystals of melting point 87°-89° C.

EXAMPLE 3

(1-R*,2-S*)-1-(5-Methyl-1,3-dioxan-5-yl)-2-(1,2,4-triazol-1-yl)-6-(2-fluorophenoxy)-hexan-1-ol(compound no. 3 in the Table)

A solution of 8.0 g (0.021 mole) of1-(5-methyl-1,3-dioxan-5-yl)-6-(2-fluorophenoxy-hexan-1-one in 100 ml ofdry tetrahydrofuran is added dropwise, under nitrogen, to a stirredsolution of about 0.06 mole of n-propylmagnesium bromide, prepared in aconventional manner, in 100 ml of dry tetrahydrofuran, at the refluxtemperature. When the solution is complete, the mixture is refluxed fora further 5 hours, after which it is hydrolyzed at 0° C. by the dropwiseaddition of 50 ml of water, and 50 ml of concentrated ammonium chloridesolution are added. The mixture is extracted with three times 200 ml ofdiethyl ether, washed neutral with water, dried over magnesium sulfateand chromatographed over a silica gel column using a 9:1 metylenechloride/acetone mixture to give 3.5 g (44%) of the pure diastereomericproduct as a pale yellow oil.

¹ H-NMR (80 MHz/CDCl): =0.9 (S, 3H), 1.0-1.4 (m, 2H), 2.8 (m, 2H),2.0-2.1 (m, 2H), 3.4 (2d, 2H), 3.8-4.2 (m, 6H), 4.6-4.7 (m, 2H), 4.95(d, 1H), 6.8-7.1 (m, 4H), 7.95 (s, 1H), 8.15 (S, 1H).

A suitable characteristic feature of the R*,$* diastereomers is, forexample, the fact that in the ¹ H-NMR spectrum the signal for the 3protons of the methyl group on the dioxanyl radical occurs at 0.1-0.2ppm, whereas the corresponding signal for the R*,S* diastereromer is at0.8-1.0 ppm.

The compounds listed in the Table below were prepared by appropriatelymodifying the above data (Dia A=R*,R*-diastereomer;Dia-B=R*,S*-diastereomer).

                                      TABLE 1                                     __________________________________________________________________________     ##STR9##                                          I                          Compound                                                                            X.sub.m n R.sup.1                                                                          R.sup.2                                                                           Y    Diastereomer                                                                         Mp. [°C.]                                                                   IR(Film)[cm.sup.-1 ]                  __________________________________________________________________________    1     2-F     4 CH.sub.3                                                                         H   CO   --     91-93                                      2     2-F     4 CH.sub.3                                                                         H                                                                                  ##STR10##                                                                         A      87-89                                      3     2-F     4 CH.sub.3                                                                         H                                                                                  ##STR11##                                                                         B      Oil  3300, 2950, 2860, 1507, 1281,                                                 1259, 1165, 1034, 926, 749            4     4-F     4 CH.sub.3                                                                         H   CO   --     Oil                                        5     H       4 CH.sub.3                                                                         H   CO   --     60-62                                      6     H       4 CH.sub.3                                                                         H                                                                                  ##STR12##                                                                         A      Oil  3310, 2860, 1479, 1247, 1162,                                                 1027, 924, 755, 682                   7     H       4 C.sub.2 H.sub.5                                                                  H   CO   --     Oil                                        8     H       4 CH.sub.3                                                                         i-C.sub.3 H.sub.7                                                                 CO   --     Oil  2964, 1719, 1600, 1499,                                                       1245, 1098, 756                       9     H       4 CH.sub.3                                                                         i-C.sub.3 H.sub.7                                                                  ##STR13##                                                                         A      Oil  3300, 2962, 1601, 1499, 1474,                                                 1245, 1098, 755                       10    H       4 CH.sub.3                                                                         n-C.sub.3 H.sub.7                                                                 CO   --     Oil                                        11    2-Cl    4 CH.sub.3                                                                         H   CO   --     Oil  2950, 2860, 1745, 1580,                                                       1487, 1471, 1278, 1249,                                                       1166, 1037, 927, 750                  12    2-Cl    4 CH.sub.3                                                                         H                                                                                  ##STR14##                                                                         A      Oil  3240, 2940, 2860, 1487, 1278,                                                 1164, 1063, 926                       13    2-Cl    4 CH.sub.3                                                                         H                                                                                  ##STR15##                                                                         B      Oil  3310, 2950, 2870, 1487, 1279,                                                 1251, 1166, 1062, 749                 14    3-Cl    4 CH.sub.3                                                                         H   CO   --     Oil                                        15    3-Cl    4 CH.sub.3                                                                         H                                                                                  ##STR16##                                                                         B      Oil                                        16    4-Cl    4 CH.sub.3                                                                         H   CO   --     resin                                      17    2,6-Cl.sub.2                                                                          4 CH.sub.3                                                                         H   CO   --     resin                                      18    2,4-Cl.sub.2                                                                          4 CH.sub.3                                                                         H   CO   --     Oil  2950, 2860, 1745, 1485,                                                       1470, 1289, 1267, 1258,                                                       1166, 1162, 1066, 1034, 927           19    2,4-Cl.sub.2                                                                          4 CH.sub.3                                                                         H                                                                                  ##STR17##                                                                         A      Oil  3250, 2940, 1485, 1289, 1164,                                                 1063, 926                             20    2,4-Cl.sub.2                                                                          4 CH.sub.3                                                                         H                                                                                  ##STR18##                                                                         B      resin                                                                              3300, 2950, 1485, 1289, 1166,                                                 1062, 1034                            21    2-Cl, 4-CH.sub.3                                                                      4 CH.sub.3                                                                         H   CO   --     Oil  2950, 2860, 1720, 1502,                                                       1255, 1165, 1033, 927                 22    2-Cl, 4-CH.sub.3                                                                      4 CH.sub.3                                                                         H                                                                                  ##STR19##                                                                         A      Oil  3240, 2940, 2860, 1502, 1254,                                                 1164, 1030, 926                       23    2-Cl, 4-CH.sub.3                                                                      4 CH.sub.3                                                                         H                                                                                  ##STR20##                                                                         B      105-106                                    24    2-CH.sub.3, 4-Cl                                                                      4 CH.sub.3                                                                         H   CO   --     Oil  2940, 2860, 1719, 1494,                                                       1248, 1165, 1033, 927                 25    2-CH.sub.3, 4-Cl                                                                      4 CH.sub.3                                                                         H                                                                                  ##STR21##                                                                         A      73-76                                      26    2-CH.sub.3, 4-Cl                                                                      4 CH.sub.3                                                                         H                                                                                  ##STR22##                                                                         B      Oil  3350, 2941, 2860, 1494, 1248,                                                 1165, 1033, 926                       27    2-CH.sub.3                                                                            4 CH.sub.3                                                                         H   CO   --     resin                                      28    2-CH.sub.3                                                                            4 CH.sub.3                                                                         H                                                                                  ##STR23##                                                                         A      Oil                                        29    2-CH.sub.3                                                                            4 CH.sub.3                                                                         H                                                                                  ##STR24##                                                                         B      Oil                                        30    3-CH.sub.3                                                                            4 CH.sub.3                                                                         H   CO   --     resin                                                                              2860, 1720, 1502, 1262,                                                       1165, 1033, 927                       31    3-CH.sub.3                                                                            4 CH.sub.3                                                                         H                                                                                  ##STR25##                                                                         A      1001∝101                            32    3-CH.sub.3                                                                            4 CH.sub.3                                                                         H                                                                                  ##STR26##                                                                         B      Oil  3260, 2940, 2860, 1491, 1263,                                                 1165, 1033, 926                       33    4-CH.sub.3                                                                            4 CH.sub.3                                                                         H   CO   --     Oil                                        34    4-C.sub.2 H.sub.5                                                                     4 CH.sub.3                                                                         H   CO   --     resin                                      35    4-i-C.sub.3 H.sub.7                                                                   4 CH.sub.3                                                                         H   CO   --     Oil  2958, 2868, 1745, 1512,                                                       1243, 1166, 1034, 927, 829            36    4-i-C.sub.3 H.sub.7                                                                   4 CH.sub.3                                                                         H                                                                                  ##STR27##                                                                         A      74-77                                      37    4-i-C.sub.3 H.sub.7                                                                   4 CH.sub.3                                                                         H                                                                                  ##STR28##                                                                         B      Oil  3300, 2958, 2868, 1512, 1243,                                                 1166, 1034, 927, 829                  38    2-OCH.sub.3                                                                           4 CH.sub.3                                                                         H   CO   --     Oil  2950, 2865, 1740, 1505,                                                       1254, 1227, 1166, 1124,                                                       1031, 927, 746                        39    2-OCH.sub.3                                                                           4 CH.sub.3                                                                         H                                                                                  ##STR29##                                                                         A      117-119                                    40    2-OCH.sub.3                                                                           4 CH.sub.3                                                                         H                                                                                  ##STR30##                                                                         B      Oil  3260, 2940, 1506, 1253, 1165,                                                 1030, 745                             41    4-OCH.sub.3                                                                           4 CH.sub.3                                                                         H   CO   --     resin                                      42    4-OC.sub.2 H.sub.5                                                                    4 CH.sub.3                                                                         H   CO   --     resin                                      43    4-NO.sub.2                                                                            4 CH.sub.3                                                                         H   CO   --     Oil  2938, 2862, 1745, 1600,                                                       1499, 1245, 1187, 1084,                                                       1034, 927, 757                        45    H       5 CH.sub.3                                                                         H                                                                                  ##STR31##                                                                         A      Oil  3120, 2940, 1499, 1245, 1163,                                                 1027, 926, 753                        46    H       5 CH.sub.3                                                                         H                                                                                  ##STR32##                                                                         B      88-90                                      47    2-F     5 CH.sub.3                                                                         H   CO   --     Oil  2940, 1725, 1507, 1457,                                                       1279, 1259, 1166, 1035,                                                       937, 750                              48    2-F     5 CH.sub.3                                                                         H                                                                                  ##STR33##                                                                         A      Oil  3250, 2940, 1507, 1259, 1164,                                                 1034, 750                             49    2-F     5 CH.sub.3                                                                         H                                                                                  ##STR34##                                                                         B      78-80                                      50    H       3 CH.sub.3                                                                         i-C.sub.3 H.sub.7                                                                 CO   --     Oil  2963, 1719, 1600, 1499,                                                       1245, 1098, 755                       51    H       3 CH.sub.3                                                                         i-C.sub.3 H.sub.7                                                                  ##STR35##                                                                         A      110-114                                    52    H       3 CH.sub.3                                                                         H   CO   --     Oil  2860, 1720, 1599, 1500,                                                       1245, 1166, 1033, 927, 757            53    H       3 CH.sub.3                                                                         H                                                                                  ##STR36##                                                                         A      68-70                                      54    H       3 CH.sub.3                                                                         H                                                                                  ##STR37##                                                                         B       95-100                                    55    3-F     3 CH.sub.3                                                                         H   CO   --     Oil                                        56    2-F     3 CH.sub.3                                                                         H   CO   --     Oil  2860, 1720, 1506, 1259,                                                       1165, 1034, 927, 751                  57    2-F     3 CH.sub.3                                                                         H                                                                                  ##STR38##                                                                         A      Oil  3250, 2860, 1507, 1259, 1164,                                                 1032, 926, 750                        58    2-F     3 CH.sub.3                                                                         H                                                                                  ##STR39##                                                                         B      125-127                                    59    2,4-Cl.sub.2                                                                          3 CH.sub.3                                                                         H   CO   --     resin                                      60    3-CH.sub.3                                                                            3 CH.sub.3                                                                         H   CO   --     Oil  2860, 1720, 1502, 1262,                                                       1165, 1033, 927                       61    3-CH.sub.3                                                                            3 CH.sub.3                                                                         H                                                                                  ##STR40##                                                                         A      100-103                                    62    3-CH.sub.3                                                                            3 CH.sub.3                                                                         H                                                                                  ##STR41##                                                                         B      103-106                                    63    4-CH.sub.3                                                                            3 CH.sub.3                                                                         H   CO   --     Oil  2860, 1720, 1512, 1243,                                                       1106, 1033, 927                       64    4-CH.sub.3                                                                            3 CH.sub.3                                                                         H                                                                                  ##STR42##                                                                         A      102-104                                                                            3230, 2859, 1512, 1243, 1164,                                                 1031, 926                             65    4-CH.sub.3                                                                            3 CH.sub.3                                                                         H                                                                                  ##STR43##                                                                         B      105-107                                    66    4-C.sub.6 H.sub.5                                                                     3 CH.sub.3                                                                         H   CO   --     resin                                      67    4-NO.sub.2                                                                            3 CH.sub.3                                                                         H   CO   --     resin                                      68    4-OC.sub.2 H.sub.5                                                                    3 CH.sub.3                                                                         H   CO   --     resin                                      69    2-Cl, 4-CH.sub.3                                                                      3 CH.sub.3                                                                         H   CO   --     Oil  2860, 1721, 1502, 1255,                                                       1166, 1033, 927                       70    2-Cl, 4-CH.sub.3                                                                      3 CH.sub.3                                                                         H                                                                                  ##STR44##                                                                         A      100-103                                    71    2-Cl, 4-CH.sub.3                                                                      3 CH.sub.3                                                                         H                                                                                  ##STR45##                                                                         B      152-154                                    72    2-CH.sub.3, 4-Cl                                                                      3 CH.sub.3                                                                         H   CO   --     Oil  2860, 1721, 1495, 1248,                                                       1191, 1165                            73    2-CH.sub.3, 4-Cl                                                                      3 CH.sub.3                                                                         H                                                                                  ##STR46##                                                                         A      135-138                                    74    2-CH.sub.3, 4-Cl                                                                      3 CH.sub.3                                                                         H                                                                                  ##STR47##                                                                         B      Oil  3200, 2860, 1494, 1248, 1165,                                                 1033, 926                             75    2-CH.sub.3, 4-CH.sub.3                                                                4 CH.sub.3                                                                         H   CO   --     Oil  2940, 2866, 1719, 1503,                                                       1254, 1165, 1034, 927                 76    2-CH.sub.3, 4-CH.sub.3                                                                4 CH.sub.3                                                                         H                                                                                  ##STR48##                                                                         A      68-70                                      77    2-CH.sub.3, 4-CH.sub.3                                                                4 CH.sub.3                                                                         H                                                                                  ##STR49##                                                                         B      Oil  3270, 2941, 2861, 1505, 1254,                                                 1165, 1033, 926                       78    2-CH.sub.3, 4-CH.sub.3                                                                3 CH.sub.3                                                                         H   CO   --     Oil  2860, 1721, 1504, 1258,                                                       1228, 1166, 1033, 927                 79    2-CH.sub.3, 4-CH.sub.3                                                                3 CH.sub.3                                                                         H                                                                                  ##STR50##                                                                         A      75-78                                      80    2-CH.sub.3, 4-CH.sub.3                                                                3 CH.sub.3                                                                         H                                                                                  ##STR51##                                                                         B      116-118                                    81    H       2 CH.sub.3                                                                         H   CO   --     resin                                      82    H       2 CH.sub.3                                                                         H                                                                                  ##STR52##                                                                         A      resin                                                                              3240, 2840, 1580, 1480,  1240,                                                1150, 1040, 920, 750                  83    H       2 CH.sub.3                                                                         H                                                                                  ##STR53##                                                                         B      resin                                      84    H       2 CH.sub.3                                                                         i-C.sub.3 H.sub.5                                                                 CO   --     Oil  2960, 1718, 1600, 1500,                                                       1244, 1098, 1005, 756                 85    H       2 CH.sub.3                                                                         i-C.sub.3 H.sub.5                                                                  ##STR54##                                                                         A      119-124                                    86    2-F     2 CH.sub.3                                                                         H   CO   --     Oil  2860, 1740, 1507, 1166,                                                       1034, 927, 752                        87    2-F     2 CH.sub.3                                                                         H                                                                                  ##STR55##                                                                         A      69-72                                                                              3250, 2855, 1507, 1260, 1164,                                                 1033, 926, 750                        88    2-F     2 CH.sub.3                                                                         H                                                                                  ##STR56##                                                                         B      Oil  3300, 2850, 1507, 1260, 1165,                                                 1034, 926, 750                        89    4-F     2 CH.sub.3                                                                         H   CO   --     Oil                                        90    2-Cl    2 CH.sub.3                                                                         H   CO   --     Oil                                        91    4-Cl    2 CH.sub.3                                                                         H   CO   --     Oil  2840, 1700, 1480, 1230,                                                       1160, 1020, 920, 820                  92    4-Cl    2 CH.sub.3                                                                         H                                                                                  ##STR57##                                                                         A      121-123                                    93    4-Br    2 CH.sub.3                                                                         H   CO   --     Oil                                        94    4-Br    2 CH.sub.3                                                                         H                                                                                  ##STR58##                                                                         A      129-131                                    95    4-CN    2 CH.sub.3                                                                         i-C.sub.3 H.sub.5                                                                 CO   --     Oil  2960, 2226, 1740, 1607,                                                       1509, 1258, 1174, 1097, 1005          96    4-CN    2 CH.sub.3                                                                         i-C.sub.3 H.sub.7                                                                  ##STR59##                                                                         A      110-118                                    97    2-CF.sub.3                                                                            2 CH.sub.3                                                                         H   CO   --     Oil  2860, 1750, 1609, 1500,                                                       1461, 1323, 1278, 1166,                                                       1119, 1037                            98    2-CF.sub.3                                                                            2 CH.sub.3                                                                         H                                                                                  ##STR60##                                                                         A       99-104                                    99    2-CF.sub.3                                                                            2 CH.sub.3                                                                         H                                                                                  ##STR61##                                                                         B      112-117                                    100   4-CF.sub.3                                                                            2 CH.sub.3                                                                         H    CO  --     Oil                                        101   4-CF.sub.3                                                                            2 CH.sub.3                                                                         H                                                                                  ##STR62##                                                                         A      Oil                                        102   2-CH.sub.3                                                                            2 CH.sub.3                                                                         H   CO   --     Oil  2860, 1722, 1497, 1245,                                                       1165, 1123, 1032, 927, 755            103   2-CH.sub.3                                                                            2 CH.sub.3                                                                         H                                                                                  ##STR63##                                                                         A      74-77                                                                              3260, 2850, 1497, 1245, 1164,                                                 1086, 1032, 926                       104   2-CH.sub.3                                                                            2 CH.sub.3                                                                         H                                                                                  ##STR64##                                                                         B      131-133                                    105   3-CH.sub.3                                                                            2 CH.sub.3                                                                         H   CO   --     Oil  2860, 1721, 1491, 1262,                                                       1165, 1033, 927                       106   3-CH.sub.3                                                                            2 CH.sub.3                                                                         H                                                                                  ##STR65##                                                                         A      79-81                                      107   3-CH.sub.3                                                                            2 CH.sub.3                                                                         H                                                                                  ##STR66##                                                                         B      97-98                                      108   2,4-Cl.sub.2                                                                          2 CH.sub.3                                                                         H   CO   --     108-110                                    109   2,4-Cl.sub.2                                                                          2 CH.sub.3                                                                         H                                                                                  ##STR67##                                                                         A      122-124                                    110   2,4,6-Cl.sub.3                                                                        2 C.sub.2 H.sub.5                                                                  H   CO   --     resin                                      111   2-Cl, 4-CH.sub.3                                                                      2 CH.sub.3                                                                         H   CO   --     Oil  2860, 1723, 1502, 1166,                                                       1033, 927                             112   2-Cl, 4-CH.sub.3                                                                      2 CH.sub.3                                                                         H                                                                                  ##STR68##                                                                         A      101-103                                    113   2-Cl, 4-CH.sub.3                                                                      2 CH.sub.3                                                                         H                                                                                  ##STR69##                                                                         B      Oil  3260, 2860, 1502, 1166, 1033,                                                 926                                   114   2-CH.sub.3, 4-Cl                                                                      2 CH.sub.3                                                                         H   CO   --     88-90                                      115   2-CH.sub.3, 4-Cl                                                                      2 CH.sub.3                                                                         H                                                                                  ##STR70##                                                                         A      102-105                                    116   2-CH.sub.3, 4-Cl                                                                      2 CH.sub.3                                                                         H                                                                                  ##STR71##                                                                         B      121-123                                    117   2-CH.sub.3, 4-CH.sub.3                                                                2 CH.sub.3                                                                         H   CO   --     Oil  2860, 1721, 1505, 1255,                                                       1165, 1033, 925                       118   2-CH.sub.3, 4-CH.sub.3                                                                2 CH.sub.3                                                                         H                                                                                  ##STR72##                                                                         A      73-76                                      119   2-CH.sub.3, 4-CH.sub.3                                                                2 CH.sub.3                                                                         H                                                                                  ##STR73##                                                                         B      75-78                                      120   2-OCH.sub.3, 4-CH.sub.3                                                               2 CH.sub.3                                                                         H   CO   --     resin                                                                              2860, 1720, 1512, 1266,                                                       1164, 1140, 1034, 927                 121   2-OCH.sub.3, 4-CH.sub.3                                                               2 CH.sub.3                                                                         H                                                                                  ##STR74##                                                                         B      resin                                      122   2-OCH.sub.3, 4-CH.sub.3                                                               2 CH.sub.3                                                                         H                                                                                  ##STR75##                                                                         B      resin                                                                              3280, 2960, 1512, 1164, 1033,         __________________________________________________________________________                                            926                               

To determine the growth-regulating property of the test substances, testplants were grown on a culture substrate provided with sufficientnutrients, in plastic containers about 12.5 cm in diameter.

The substances to be tested were sprayed as an aqueous formulation ontothe plants by the post-emergence method. The growth-regulating effectobserved was supported at the end of the experiment by measuring thegrowth in height. Measured values obtained in this manner were expressedas a ratio of the growth in height of the untreated plants. Thecomparative substances used were chlorocholine chloride and the activeingredients denoted below by B, C and D.

Parallel with the reduction in the growth in height, the color intensityof the leaves increased. Because of the increased chlorophyll content, ahigher rate of photosynthesis and hence a greater yield are alsoexpected.

Comparatives substances:

    __________________________________________________________________________    A Chloroquinoline chloride of the formula                                                     ##STR76##                                                                     ##STR77##                                                     C                                                                                             ##STR78##                                                     D                                                                                             ##STR79##                                                     __________________________________________________________________________

In experiments with spring barley, sunflowers and summer rape, and inthe rice seedling test, it was found that, at application rates of 1.5and 6 mg of active ingredient per container, the compounds 3, 5, 8, 9,50, 51, 82, 84, 85, 92, 95, 96, 108, 109, 114 and 115 all had a moreadvantageous and reduction in the height of growth.

We claim:
 1. A compound of the formula I ##STR80## where R¹ and R² areidentical or different and are each hydrogen or alkyl of 1 to 5 carbonatoms, X is an identical or different substituent selected from thegroup consisting of halogen, cyano, trifluoromethyl, nitro, C₁ -C₄-alkyl, C₁ -C₄ -alkoxy, unsubstituted phenyl or hydrogen, m is from zeroto 5, n is an integer from 2 to 6 and Y is --CO-- or --CH(OH)--.
 2. Acompound of the formula I as defined in claim 1, wherein X is hydrogen,2-fluoro-, 4-fluoro-, 2-chloro-, 3-chloro-, 4-chloro-, 4-bromo-,2,4-dichloro-, 2,6-dichloro-, 3,4-dicholoro-, 2,4,6-trichloro-,2-chloro-4-methyl-, 2-methyl-4-chloro-, 2-methyl-, 3-methyl-, 4-methyl-,4-ethyl-, 4-isopropyl-, 4-tert-butyl-, 2,4-dimethyl-, 2,4,6-trimethyl-,2-methoxy-4-methyl-, 2-methoxy-, 4-methoxy-, 4-ethoxy-,2-trifluoromethyl-, 4-trifluoromethyl-, 4-cyano-, 4-nitro- or 4-phenyl-,R¹ is methyl or ethyl and R² is hydrogen, methyl, ethyl, n-propyl,isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl orneopentyl.
 3. A method of reducing the height of growing plants whichcomprises: applying to the plants or their habitat an effective amountof one or more compounds of the formula I as defined in claim
 1. 4. Amethod of reducing the height of growing plants which comprises:applying to the plants or their habitat an effective amount of one ormore compounds of the formula I as defined in claim
 2. 5. A compositionfor reducing the height of growing plants which comprises: an effectiveamount of one or more compounds of the formula I as defined in claim 1,and an inert liquid or solid carrier.